Python 3.6 now requires inttypes.h on all platforms.  However, this is not provided by MSVC 2010 and 2012, which is still used by some people who build extension modules for Python.

MSVC 2010 does provide stdint.h, and replacing the inttypes.h include with an include to stdint.h seems to work fine.

I would suggest a fix along the lines of this:

#if defined(_MSC_VER) && _MSC_VER < 1800
#include <stdint.h>
#else
#include <inttypes.h>
#endif

Alternatively, the HAVE_INTTYPES_H definition could be used to fall back to stdint.h, and it could be undefined for the MSVC build.

VS 2010 is not a supported compiler version for 3.6 (or 3.5) and VS 2012 is not a supported compiler for any version of Python. Extension modules built by those versions for use with Python 3.6 as supplied by python.org will only work in very particular circumstances which cannot be relied upon. Furthermore, VS 2015 community edition is free (as in beer) and perfectly suitable for building both Python and extension modules.

I'd recommend closing as won't fix, but if another committer feels strongly enough about it I'll defer to them.

Everything Zach said is accurate, so closing as "wont fix".

As far as I know, there should not be any ABI issues.  We've been building extension modules with non-matching MSVC versions for years without issues.

I find it hard to think of downsides to such a trivial fix.  It is somewhat frustrating that we will have to resort to shipping custom Python versions with patched headers.  Some people are constrained to older MSVC versions for reasons not in their control.